From 544515c2a6bd44454bbdb86829e5b63da798fd71 Mon Sep 17 00:00:00 2001
From: jamesread <contact@jread.com>
Date: Sun, 15 Feb 2026 00:19:36 +0000
Subject: [PATCH] chore: #829, json support in template engine

---
 service/internal/tpl/templates.go      | 15 ++++-
 service/internal/tpl/templates_test.go | 81 ++++++++++++++++++++++++++
 2 files changed, 95 insertions(+), 1 deletion(-)
 create mode 100644 service/internal/tpl/templates_test.go

diff --git a/service/internal/tpl/templates.go b/service/internal/tpl/templates.go
index 580b907..cb9978f 100644
--- a/service/internal/tpl/templates.go
+++ b/service/internal/tpl/templates.go
@@ -1,6 +1,7 @@
 package tpl
 
 import (
+	"encoding/json"
 	"fmt"
 	"regexp"
 	"strings"
@@ -12,8 +13,20 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+func jsonFunc(v any) (string, error) {
+	if v == nil {
+		return "null", nil
+	}
+	data, err := json.Marshal(v)
+	if err != nil {
+		return "", err
+	}
+	return string(data), nil
+}
+
 var tpl = template.New("tpl").
-	Option("missingkey=error")
+	Option("missingkey=error").
+	Funcs(template.FuncMap{"Json": jsonFunc})
 
 type olivetinInfo struct {
 	Build   *installationinfo.BuildInfo
diff --git a/service/internal/tpl/templates_test.go b/service/internal/tpl/templates_test.go
new file mode 100644
index 0000000..d46f902
--- /dev/null
+++ b/service/internal/tpl/templates_test.go
@@ -0,0 +1,81 @@
+package tpl
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/OliveTin/OliveTin/internal/entities"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseTemplateWithActionContext_Json(t *testing.T) {
+	tests := []struct {
+		name           string
+		source         string
+		ent            *entities.Entity
+		args           map[string]string
+		expectedOutput string
+		expectError    bool
+		checkJsonOnly  bool
+	}{
+		{
+			name:           "Arguments piped to Json",
+			source:         `echo {{ .Arguments | Json }}`,
+			ent:            nil,
+			args:           map[string]string{"value": "true", "ot_username": "alice"},
+			expectedOutput: `echo `,
+			expectError:    false,
+			checkJsonOnly:  true,
+		},
+		{
+			name:           "CurrentEntity field piped to Json",
+			source:         `curl -d {{ .CurrentEntity.foo.bar | Json }}`,
+			ent:            &entities.Entity{Data: map[string]any{"foo": map[string]any{"bar": "baz"}}},
+			args:           nil,
+			expectedOutput: `curl -d "baz"`,
+			expectError:    false,
+		},
+		{
+			name:           "CurrentEntity nested object piped to Json",
+			source:         `curl --json -d {{ .CurrentEntity.payload | Json }}`,
+			ent:            &entities.Entity{Data: map[string]any{"payload": map[string]any{"on": true}}},
+			args:           nil,
+			expectedOutput: `curl --json -d {"on":true}`,
+			expectError:    false,
+		},
+		{
+			name:           "Single argument value as Json",
+			source:         `echo {{ .Arguments.value | Json }}`,
+			ent:            nil,
+			args:           map[string]string{"value": "hello"},
+			expectedOutput: `echo "hello"`,
+			expectError:    false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := ParseTemplateWithActionContext(tt.source, tt.ent, tt.args)
+			if tt.expectError {
+				assert.Error(t, err)
+				return
+			}
+			assert.NoError(t, err)
+			if tt.checkJsonOnly {
+				prefix := strings.TrimSuffix(tt.expectedOutput, " ")
+				assert.True(t, strings.HasPrefix(output, prefix), "output %q should start with %q", output, prefix)
+				jsonPart := strings.TrimPrefix(output, prefix)
+				jsonPart = strings.TrimSpace(jsonPart)
+				var decoded map[string]string
+				err := json.Unmarshal([]byte(jsonPart), &decoded)
+				assert.NoError(t, err)
+				for k, v := range tt.args {
+					assert.Equal(t, v, decoded[k], "decoded JSON should contain %s=%s", k, v)
+				}
+				assert.Len(t, decoded, len(tt.args))
+			} else {
+				assert.Equal(t, tt.expectedOutput, output)
+			}
+		})
+	}
+}